In this exercise, we'll look at the Reds player that best exemplifies each level of tradability.
Must Keep: Devin Mesoraco
You could make the argument that Mesoraco should be the odd man out in the catcher conundrum, but his trade value has never been lower. He's played well enough to earn a shot at a starting job, and there's no reason why that shouldn't be with the Reds at this point.
Should Keep: Aroldis Chapman
You didn't even think he'd be in this article, did you? While the Reds could use Chapman in a variety of ways, I think this is the first offseason where he shouldn't be deemed "untouchable". He's getting to the point where he's getting pretty expensive to provide something you already have in both a full rotation and a big-money bullpen. Reds fans know what he's capable of, so it'd take a pretty huge haul for another team to get him, but if he's the centerpiece of the right deal it's defensible.
Neutral: Homer Bailey
Another player who's about to be a little more expensive than he needs to be. You'd still be selling high, but if you kept him, he'd be a solid #3 starter for you. I could go either way on this one.
Should Trade: Brandon Phillips
As much as we enjoy having him on the team, BP looks to have one foot out the door. I'd really prefer the Reds kept him, as there's no way they find his production anywhere on the open market, but that contract is such that they'd really benefit to move him. At this point, we've heard enough of these rumors that I've already accepted it as something that's going to happen. As long as that doesn't mean "starting 2B Skip Schumaker".
Must Get Rid Of: Ryan Hanigan
Hanny's been a loyal servant to the Reds, but there just isn't enough room at the inn for 3 catchers. We'll miss his ability to call a game, and the weird telepathy thing he had with Bronson Arroyo, but it's Devin's turn. His contract is tradable enough, too.